Day10 大球吃小球初始bug优化

获得鼠标初始位置x, y，界面的高宽h, w,
当 h,w - y, x < radius or h,w - y,x >(h - self.radius, w - self.radius)
【即初始位置的小球部分在界面外】
小球无法正常运动

修改def move()代码如下，优化此问题：

    def move(self, screen):
        self.x += self.sx
        self.y += self.sy
        temp_sx = self.sx
        temp_sy = self.sy

        w, h = pygame.display.get_surface().get_size()
        if w - self.x <= self.radius:
            self.sx = -abs(self.sx)
        elif w - self.x <= w - self.radius:
            self.sx = temp_sx
        else:
            self.sx = abs(self.sx)

        if h - self.y <= self.radius:
            self.sy = -abs(self.sy)
        elif h - self.y <= h - self.radius:
            self.sy = temp_sy
        else:
            self.sy = abs(self.sy)

Start by locating the Day 10 ball class and its move(self, screen) method, then compare its boundary handling with the conditions and replacement shown in the issue. Run the game with a ball initially partly outside the screen and confirm it can move normally and respond to the screen edges.